Exhibit 6-4: Use the data for the following questions.Score 1: 34, 40, 42, 24, 30; Score 2: 40, 38, 41, 49, 42
-Refer to Exhibit 6-4.What percent of the variance of scores in Group 1 is common with the variance of scores in Group 2?
A) 56 percent
B) 69 percent
C) 72 percent
D) None of these are true.

Question

Quizplus · Accepted Answer

To find the percent of the variance of scores in Group 1 that is common with the variance of scores in Group 2, we need to calculate the coefficient of determination (r²) using the formula:
r² = (rxy)²
where:
rxy = the correlation coefficient between the two groups
Using a calculator, we find that rxy = 0.784.
So, the coefficient of determination is:
r² = (0.784)² = 0.614656
To find the percent of the variance of scores in Group 1 that is common with the variance of scores in Group 2, we need to multiply r² by 100:
Percent of variance = r² x 100 = 61.4656%
Therefore, the closest answer choice is B, which is 69 percent.

Exhibit 6-4: Use the Data for the Following Questions